D. All brakes, axles and suspensions are certified for weight capacity by a final stage manufacturer. The certification must be presented before the permit is issued. The certification must be affixed to or carried in the vehicle and presented on request to a state police officer; and

E. A general commodity permit is obtained. The permit must be carried in the vehicle at all times. The fee for an annual permit is $252; a 3-month permit is $75; and a permit for a period of 4 months or more is $21 per month. A permit may be transferred to another vehicle for an additional fee of $2.

The permit may be obtained from a branch office of the Secretary of State, Bureau of Motor Vehicles, or from an agent appointed by the Secretary of State. A municipal agent may charge an additional $1 and may retain that sum as compensation.

Revenue from the permit fee must be expended for the enforcement of truck weight regulations.

Nothing contained in this subsection applies to vehicles using the Interstate Highway System as defined in the Federal Aid Highway Act of 1956.

For vehicles operating under this subsection gross vehicle weight violations are determined on the basis of 90,000 pounds.

For all vehicles manufactured, modified or retrofitted with liftable or variable load suspension axles after October 30, 1991, liftable or variable load suspension axles are permitted only under the following conditions: only one liftable or variable load axle may be present on the truck tractor and only one liftable or variable load axle may be present on the semitrailer; liftable or variable load axles must be located on the vehicle so that they are legally part of the tandem axle group or tri-axle group as appropriate; and the axle weight rating of liftable or variable load axles must conform to the expected loading of the suspension and must be 20,000 pounds or more.

Sec. 8. 29-A MRSA §2357, sub-§4, as enacted by PL 1993, c. 683, Pt. A, §2 and affected by Pt. B, §5, is amended to read:

4. Six-axle combination. Notwithstanding subsection 2, a 6- axle combination vehicle, consisting of a 3-axle truck tractor